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What is the GE90-115b turbine power output in horsepower?
The GE90-115b is rated at 513 kN maximum thrust and is often said to have 110,000 shaft horsepower, but I have yet to find any document or specification that backs the claim on horsepower figure.
A comparable engine, the Trent XWB-97 rated at 430 kN and puts out 50,000 shp according to the Rolls-Royce website.
The vast difference in horsepower 50,000 shp vs 110000 shp and not all that huge difference in thrust 430 kN vs 513 kN makes me suspicious if the GE90 actually puts out 110,000 or if this has become a "thing" for the GE90 without being correct. Or, perhaps shaft horsepower and turbine horsepower is not the same?
Does the GE90-115b actually output 110,000 shp?

According to the GE website for the GE90-110/115 the engines ran at 127,000lb-thrust at "triple redline conditions" for 60 hours. So what you may be seeing is the difference between "maximum thrust" and "rated thrust". The GE90-110/115 puts out around 74-94,000lb-thrust.

@RonBeyer so the GE90 is rated at 115,000lb maximum and 94,000 continuous if I understood you correctly? The XWB-97 is rated at 430 kN maximum and 370 kN continuous. But, if we compare maximum numbers and not continuous, that means we're looking at XWB97 with 430 kN vs GE90 with 513, (although 569 kN was achieved once) - but thats only ≈ 80-130 kN difference, compared to the massive 60,000 shaft horsepower difference if we are to believe the articles.

Talking about jet engines in HP really doesn't make much sense, but media likes to do it. Power is forcedistance/time or ForceSpeed. So at 0 speed, you get 0 power. At takeoff speed and full thrust you get around 55,000 HP for GE90-115B, while your thrust actually decreases the faster you go. The actual fan shaft will transfer around 30,000 HP from the LP turbine to the Fan, internal to the engine.

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According to the GE website, they used a GE90-115B as a power generation unit, called the LM9000. GE cited 65,000 horsepower, which seems to scale rather reasonably when compared to the RR Trent XWB.

+1, however, I don't think that power generators like LM9000 would operate at full power. I believe that they would operate at power settings below max continuous, so maybe GE90's actual power is much more than 65k HP.

TLDR
The number given for the Trent engine is only for a specific engine component and is not representative for the total output of that engine. The 110000 hp for GE90 is plausible.
Full answer
It is not as natural to compare shaft horsepower for turbofans as it is for piston or turboprop engines, where it is canonical to measure the shaft power delivered to the propeller.
The Trent engine
Looking at the source cited for the Trent engine in the question, the 50000 horsepower figure is "Horsepower generated by 68 high pressure turbine blades". I think that means 50000hp is extracted by the HP turbine. This does not contribute directly to thrust, as most of that power would be used by the compressor. The Trent is actually a three spool engine, I cannot tell if this figure includes the IP turbine or not, but the same goes for the IP as the HP turbine, most of the power extracted is used by the compressor. The fan, which does most of the propulsion, is powered by the low pressure turbine.
Similarly, the high pressure turbine would not contribute directly to the output of a derived turboshaft.
Power of GE90
That leaves the question of what is actually meant by 110000 hp. This could be the shaft power being transferred by both the spools combined, the power delivered to the fan, or the work done in propelling the airplane, i.e. thrust*speed at some chosen conditions.
I would argue the most natural thing is to measure the work done on the air mass propelled by the engine, i.e. the kinetic energy of the air leaving a static engine over one second, for a static engine at full thrust at STP.
Now we can attempt an estimate of this for the GE90-115. For this we need to know the mass flow rate and exit velocity.
According to this the specific thrust for a kg of air is 278 N*s(=m/s) in those conditions for an earlier less powerful GE90 variant. Assuming GE90-115 has the same exit velocities, at 513 kN that would give a mass flow of 513000/278=1845 kg/s.  Then the power is 2782 * 1845/2 W, which is approximately 71.3 MW, or 95600 hp.
The exit velocities of the air leaving the core nozzle and bypass nozzle are actually different, which means the above is a slight underestimate. Given that and the fact that our exit velocity is from a speculative source assessing a different GE90 variant, this is not too far off the 110000 figure.

I guess "shaft horsepower" suddenly becomes "natural" when you turn the GE 90 into a generator?  We can actually determine "shaft horsepower" in Newton meters/second as the exact same number as compressor drag × radius/second + fan drag × radius/second.  But, thanks for showing that work is being done by moving air even if the engine is stationary.

@ Aditya Sharma  I am linking to a source using this same mass flow number, 1350 kg/s. This is the mass flow of an earlier GE90 variant delivering 388kN takeoff thrust, but the question explicitly mentioned the GE90-115b. I don't have a better source so I scaled the mass flow up proportional with the thrust increase.

@ÖgmundurEiriksson very interesting information, thanks for sharing :-)

A "Rosetta Stone" of high subsonic Thrust Specific Fuel consumption and Power Specific Fuel consumption can be found by reviewing data for the Progress D 27 turbo prop engine: 11g/(kNewton second) and 0.14 kg/(HP hour)
Working through some math:
11 g/(kN second) × 1 kg/1000 g × 3600 seconds/hour × 1 kN/1000 N x 1 N/.225 lb force we have 0.176 kg/(lb force hour).
Comparing this to 0.140 kg/(Hp hour) for a turboprop shows (sadly) that the "3 pounds thrust per horsepower" efficiency enjoyed by props$^1$ at less than Mach 0.5 declines to less than 1 pound of thrust per HP$^2$.
But, comparing apples to apples, the SFC of the Jumo 004 is:
143 kg/(kN hour) × 1000 g/kg × 1 hour/3600 seconds) = 40 g/(kN second)
The LEAP engine that powers the 737, and the GE 90 of the 777, use around  15 g/(kN second) in cruise.
Efficiency is why "old time" Horsepower is rarely applied to jet engine thrust.  Although the D-27 SFC of 11 g/(kN second) is less than the LEAP, it is only had at a lower speed (450 knots vs 520 knots).
$^1$ the 1600 lb propeller driven Helios flew to over 90,000 feet with 28 Horsepower.  It's indicated airspeed was around 22 knots (300+ True airspeed)!
$^2$ see Ron Beyer comment under the question.

I think the numbers (93.7khp) are accurate (https://www.geaviation.com/commercial/engines/ge90-engine).
I recall numbers from CFM56 (smaller engine) being something like 10khp for the fan and 20khp for the core so like 2/3 for the core and 1/3 for the fan (can't find where i saw that, but it was definitly shaft power).
On the Trents it is said 50 khp from "high power turbine blades", so i'm guessing it might be the hp core shaft power which is probably like the CFM, something like 2/3 of total engine power which would put it at 75 khp and GE90 core power around 62.5khp which matches the number given (65 khp) for the LM9000 (core technology similar to that of the GE90).

I think that horse power of GE90 is about 97.000 hp (65.000 kW = 88.000 hp). I have a book about the Concorde which at cruise has a certain air resistance. I calculated that the engine had to produce 90.000 hp to maintain that speed. Efficiency of the Olympus engines at cruise was 40%, a high value for a turbo jet (no fan). Many turbojet/fan engines are used to drive a propeller. In these cases we measure the power in kW (or hp). GE's engines often exist also as stationary engines to drive a generator or a pump. Then power are measured in kW. One may think that these engines take out less power because the shall work months continually (but I do not know).

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@KETILLJACOBSEN please show your Concorde calculations starting with "air resistance".


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What does a passenger aircraft galley ('kitchen') look like?
What equipment is installed in passenger aircraft for catering the passenger?

BEA galleys - A321 - More Galleys on Youtube

My recommendation would be to check out the market leader, Sell GmbH in Herborn, Germany. Their website is hosted by their French owners.

An aircraft Kitchen is known as the Galley and the picture is from a Lufthansa A380.
Some equipment you will see here are:

Food Oven, the door with a black knob in the middle of the picture.
Coffee Machine, with the pot, in the right side of the picture.
Large Trolleys, filled with food and/or drinks, on the floor. Weight about 25kg empty.
Trash Bin, the darker grey unit on the right on the floor. Wheeled off like everything else. Some have proper trash electric trash compactors as well in trolley format.
Fuse Panel, located in the middle along the top row. There is in general a fair bit of power going into this area.
Smaller Storage Containers, that can handle drinks or bottles for instance.
General Storage Space: The galley also provides a bit of space for anything from the children's toys and newspapers to emergency equipment. You can see some compartments for this in the upper-left corner and a symbol that a smoke hood is stored in one of them.

Quick design comment:
Aircraft galleys are hotspots for corrosion due to the liquid in the area and is the cause for particular attention during maintenance. Most aircraft galleys are generally very similar in design.

Galley equipment comes in 2 basic universal standards - namely ATLAS and KSSU. These have their origins in legacy maintenance resource pools (ATLAS = Alitalia, TAP, Lufthansa, Air France, Sabena and KSSU = KLM, Swissair, SAS, UTA) and have subsequently developed into industry standards to enable modular equipment interchange.

These standards for instance specify the height, width and depth of trolleys. I gather that ATLAS standard is more prevalent (80% of galleys by one source) but both exist. Other ideas and concepts have popped up but since changing the stuff is very expensive there's not been a real push for it. I think I've also read that the original standard was pretty well thought through.
Naturally, this is a long-distance galley that will serve usually two meals. Equipment and size are scaled to the needs of the airline and can vary greatly between operators.

Further: About 80% of airline galleys are based on the ATLAS standard which defines the shape of the trays and trolleys used for loading food. This imposes the dimensions of the modular elements of the galley. Other standards include KSSU, ARINC and SPICE (based on ATLAS trays).

@RedGrittyBrick Remember reading about that, will add a bit on it :)

"The grey unit" had me puzzled for a second, since they all look rather gray to me. :)

Not all grey. Some of the parts/panels - edges on the trolleys, oven door - appear to me to have a sort of an anodized (slightly gold-ish) color.

I've noticed on some flights they block the cockpit doors with a trolley from the galley. Anyone know what protocol that is? Other times I see them just blocking it with their bodies. Why the difference?

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Where is the fuel stored on an aircraft’s wing?
Maybe guys could provide me with a picture I originally thought the anti-shock pads were fuel tanks, but somebody recently told me that they are stored in the wing, so where are they stored at. The aircraft I refer to are like the (b737), (b747-8)(b787)(a-350)

This depends on the aircraft. In many cases there is a tank inside the wing. In some cases it can be stored in a soft bladder in the wing and in other cases the wing its self is the tank.
Here is an in wing tank

Here are some in wing fuel bladders.

Mooney was known for having integrated fuel tanks in their wing designs. Here are some pictures of the tanks being resealed. They are notorious for needing a reseal every now and again but they do save in weight. Modern composite structures often don't lend to this design as jet fuel or avgas and composites don't really mix.

Here is a nice cutaway of the A330 to show where the tanks are.

It should be noted that you can generally pump fuel between the tanks however care must be taken when this is done because it can greatly effect the CG. This podcast has some really interesting information on how complex it was to manage the fuel weight on the Concorde and how it needed to be pumped around the tanks during various phases of the flight just to keep the plane stable.

Modern composite structures often don't lend to this design as jet fuel or avgas and composites don't really mix. - there are plenty of composites that have no problem with avgas or jet fuel. Many tip tanks on GA aircraft are a fiberglass shell within the wingtip that has fuel fittings laid into the structure. These designs are however prone to leaking if the composite structure develops hairline cracks, and repairs are often more involved than changing a bladder or resealing a metal tank.

What are the advantages of storing fuel in the wings?

@Firee: Weight distribution. The wings generate lift, but most of the weight is in the fuselage. That means there's a large bending force on the wings. Moving some of the weight out reduces that bending force. And obviously the space in wings is too small for passengers or luggage so fuel is the only thing you can realistically store in there.

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What are the aileron lengths of commercial and military aircraft?
I would like to know the aileron lengths for different aircraft, such as:

Cessna 150
Airbus A380, A320
Boeing 747, 777, 787
Lockheed Martin F-22 Raptor

I have tried to search online, but was unsuccessful in finding the values. I also tried searching in some books but couldn't find the values there either.
Any help guiding me to the books or any resources which would give me the values would be highly appreciated.

this questions seems to ask a grocery list of data and I hardly see how this would be beneficial to anyone else except for the OP

Once I get home tonight, I'll go to my hangar (where I've all these aircraft parked) to measure the lengths. Note to self: buy a measuring tape and a ladder on the way home.

You can find technical drawings for the Airbus and Boeing aircraft, and from this you can measure the sizes yourself

would you also add why you need this info, and where you will use it. if you're trying to create a "look alike model", then pictures of the aircraft would be sufficient, if you're searching for some aerodynamic studies, then you should also need the area of the surfaces, etc..

I was actually trying to theoretically estimate the minimum lengths of the ailerons needed for some aircrafts by using the maximum roll rate at the maximum deflection of the aileron, moment of inertia of the plane, wing span etc. I wanted to know the actual length of the ailerons just to validate my calculations.

For larger airliners the question can not really be answered. All Boeing (and probably most other) that I am aware of use multiple combinations of ailerons and spoilers depending on flight mode. For example, after about 250-300kt the outermost ailerons are locked out and only the middle or inner surfaces are used. This is because at high speed the outer ailerons are too sensitive and can also cause the pivoting of the leading edge of the outer wing panel in the opposite direction causing control reversal.

This is quite difficult to answer as some modern supersonic fighters  don't have just ailerons, but 'elevons', flaperons, tailerons and most of the time combine the movement of several control surfaces by computer to generate a desired effect.
Large civilian aircraft tend to have more than one pair. A relatively smaller set closer to the wing tips for slower speeds and a general large aileron closer to the wing root.
I would suggest you get a top-view of these aircraft. When you find our the length of the aircraft or wingspan you could derive it yourself through approximation.

Modern military aircraft have ailerons, but you'd be correct in your assumption that the majority of the roll control comes from the horizontal stabs.

For one...the F-16 does not have ailerons

The F18, F35, F15 and F22 all have ailerons.  The F-16 has flaperons, which combine both flaps and ailerons.


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Air to air Missile Guidance vs countermeasures
How do missiles successfully hit an air target despite the fact that nearly all Military aircraft are equipped with countermeasures.
Heat Seeker/Infrared missiles : IR Flares as countermeasure
Radar guided missile : Chaff dispersal as countermeasure
Laser guided missile : Flood Laser to blind missile as countermeasure
Which guidence system has most probability in hitting the target even when enemy deploys countermeasures, is there any guidence systems known which don't have a countermeasure?

I'm voting to close this question as off-topic because it's about weapons and weapons detection, not aviation.

So where should such questions be posted , please advise?

Basically, the missiles are engaged in a (deadly) game with the aircraft every time a missile is fired. All countermeasures are based on 'confusing' the missile homing systems to a certain extent, usually in the terminal stage. Missiles (or AD systems in general), use a number of methods to overcome this.
The general term for overcoming the countermeasures used by the aircraft is called counter-counter measure (CCM); in case of electronic warfare, electronic counter-counter measure (ECCM) is used.

In case of IR missiles, the aircraft should first know it is being targeted. The usual method is to use a Missile Approach Warning Sensor (MAWS), which detects the missile plume. However, this is not a foolproof method. As far as IR missiles are concerned, the target is usually unaware of the missile lock. The problem with laser guided short range missiles is also quite similar.
A number of newer missiles have dual/multi mode seekers (like IR/UV in Stinger), which helps it differentiate better between the target and decoy. Though decoys can mimic the target in one band (for e.g. IR), it cannot mimic in both the bands (flares have different UV signatures compared to the aircraft).
The missiles can be programmed to ignore the decoy (for e.g chaff) and lock only onto the target signature (rather than locking on to the strongest signal return).
The missiles can differentiate between the target and decoy using the differences in their trajectory.
The missile can discriminate between the target and decoy by using a higher resolution seeker.

It is quite difficult to have a system that couldn't be fooled. Though a video/TV guided missile would come quite close, it is quite impractical in real world. Some laser guided missiles are touted as 'unjammable', but this claim is questionable. Best option is to have a multi-mode seeker that locks onto the target in different regions of the electromagnetic spectrum, though this would make the missile too expensive (again, countermeasures are possible).

so in a nutshell its never certain if either CM or CCM would work.
"As far as IR missiles are concerned, the target is usually unaware of the missile lock"
But once launched it should be picked up due to its speed and small size as signature?

@user1062760 Yes. There is never 100% certainty that some method is going to work in aerial warfare. IR missiles are passive i.e. they don't emit any radiation (like radar guided missiles). If the IR missile is launched from the aircraft rear (a tail chase engagement), the pilot will never know the missile has been launched unless the MAWS picks it up. Yes, once the missile has been launched, MAWS should be able to pick it up, theoretically.

A missile which uses image correlation guidance, like the AGM 65 Maverick, cannot easily be jammed, although the target may be obscured by smoke or obstacles after launch.


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What happens if an aircraft declares an emergency while there is another aircraft ahead cleared to land?
Lets assume this situation: In a controlled airport, two aircraft are approaching for landing. #1 is about to touch the runway (let's assume it is within 1~2 miles from touch zone).
Then #2 declares a emergency.
Is there any rule that require that the first airplane starts a go around, either by its decision or by controller's?
Some assumptions:

There is enough separation from #1 to #2. If #1 was allowed to land and it successfully does, that will not significantly interfere with #2 landing.
Airfield has just one runway.
I'm limiting this to a international accepted, US and/or Brazilian rule.

My concern is that if some incident occurs with #1 on landing, like a gear collapsing, that may render the runway unsuable, causing trouble for the trailing aircraft in emergency.
Speaking in other words: Is an aircraft cleared to land even if another is approaching in a emergency situation?

Note that if the emergency in #2 is not a critical one (e.g. all engines out) #2 is likely to go around to do some checklists before attempting to land with an unstabilized approach.

This is a hypothetical question. It came up because I was listening to the ATC traffic and the tower asked to "wait for landing clearance" because another traffic is on short final. I though what would the procedure be if at exactly this moment, #2 needed to declare an emergency. I know each case is different and need to be analysed. I was just wondering if there is any rule for this kind of situation or it is just a matter of common sense between the people involved.

Song cue: "Teterboro Tower"

One point that's not an answer in itself but is relevant: if you're aware that another aircraft is making an emergency landing, you must not land until you've received (additional) clearance, even if you were already cleared to land.  In the situation you describe, the controllers would clear #1.

@keshlam poor piper 202

@DanHulme Just out of curiosity, is there a official FAA rule that codifies that?

@DanHulme  Sorry, but are you suggesting that one aircraft declaring an emergency on the Tower frequency means that all issued landing clearances are now cancelled? Even if you're at 50'? Or in the flare? I have NEVER heard of any such rule (certainly not in the US). Once you're cleared to land, that's your clearance until TOWER cancels it -- not another aircraft on frequency!

There are a lot of other factors: how long is the runway -- a controller can clear 2 aircraft to land on the same runway, as per http://aviation.stackexchange.com/a/1465/3504

No, the airport wouldn't be closed, and the #1 aircraft doesn't need to go around nor be sent around.
The risk of him shutting down the runway is very slight, and is probably of the same magnitude of risk that sending him around to hold until #2 has landed & the runway has been checked and reopened, would put him into a low-fuel emergency state.
If they are both about the same distance (actually, time) away, then the emergency aircraft has priority (assuming that he doesn't decide to hold in order to troubleshoot, burn down fuel, prepare for the landing, etc), but essentially closing the airport from the time that the emergency has been declared until the emergency aircraft lands, isn't something I've ever seen or heard of.
The runway is often closed following an emergency landing until it can be checked by an airport vehicle, to ensure that it is clear of debris, spilled fuel/oil/hydraulic fluid/etc. And if the emergency aircraft can't clear the runway under its own power, it takes time to get it towed off, possibly pinning the landing gear (to prevent unintended retraction) first. Plus there may be an evacuation after the landing. So closing the runway for some time after the emergency aircraft lands, is entirely possible.
But if the airport has planes in the pattern & the emergency aircraft is 50 miles out, it'd be better to let those who want/need to land, do so, rather than risk them running low on fuel airborne while awaiting the runway's reopening.  Same basic logic applies in the #1 / #2 scenario posed above.
If aircraft regularly had their gear collapse & shut down runways unexpectedly, that would be a different story. But that's exceedingly rare, so that isn't the contingency that all planning is based on.

I actually had a friend in a business jet declare an emergency for smoke in the cockpit, and ATC cleared them to land from quite a distance out. Their next call was "UPS 123... Actually, UPS 123, go around.".

@Lnafziger that looks a lot like some situation similar to that I described in the question! Thanks a lot for sharing this.

@Lnafziger - UPS 123 was presumably going to be in the way. That backs up the answer quite well that other aircraft will be moved if necessary, but if they aren't in the way they can carry on as normal. ATC will allow as much traffic as they are certain will not impede the under-emergency aircraft

"Cleared to land any runway"

Your question is a little vague; depends on the nature of the emergency for aircraft #2.
Declaring an emergency provides the PIC with the power to obtain priority over any other aircraft. If the PIC of aircraft #2 determined that they needed aircraft #1 to execute a go-around, then pilot of #1 aircraft would be expected to do that if able.
I will also add that this scenario is highly unlikely because required separation between the two aircraft would have already established enough time for #1 to land and clear the runway before #2 could get there - regardless of the situation.

@JonathanWalters The scenario says traffic #1 is 1-2 mi from the threshold, not that both aircraft are VFR and not radar separated.

@JonathanWalters: I consider it rude to remove a substantial part of the answer even if it is erroneous. It is much better to leave a comment with proof and let the author decide how to improve his answer. If you feel that your view is not represented by any of the answers, please post your own answer.

@JonathanWalters I second Peter's view here. I have rolled back the revision.

@JonathanWalters On the runway there is a separation requirement. #2 cannot touch down before #1 is clear of the active runway of a controlled airport.

What @Thomas says is very relevant. The PIC of the emergency acft is the boss.  What ever he wants he will get if at all possible. Even if against some rule or regulation.

"enough time for #1 to land and clear the runway" IF the landing goes well. In my question, I ask about the risk of something going wrong with #1.

@Wirewrap:  You said "#2 cannot touch down before #1 is clear of the active runway of a controlled airport."  What you said here is true under normal circumstances, but @2 declared an emergency and can indeed land.

@JonathanWalters: Yes, I reviewed and declined your edit. No harm done, and you will collect your reputation in due time, especially if you add better answers of your own.

@SkipMiller No, I did not say that you cannot touch down before #1 has vacated the active. I said there is a separation rule to that effect.

@Wirewrap in the USA it may be permissible for an aircraft to touch down while there is still a landing aircraft on the runway, or a departing aircraft airborne but still above the runway pavement.

It appears that the situation in your question is hypothetical. There are several aspects missing about the nature of the emergency, condition of the airport etc.
A typical situation will require that the airport will be ready to deal with the emergency, and clear the intended runway where the aircraft declaring emergency can land without delays. In clearing the runway, ATC can advise the #1 airplane to land and quickly clear the runway.
Again hypothetically speaking, after aircraft #2 has declared emergency, #1 can get into a situation where it would require more immediate assistance than #2.

Yes, this is all hypothetical. My question is more that if the controller/pilots should go safe and make #1 wait until #2 lands, avoiding the small (but existent) possibility that #1 messes with the runway. #1 would have no technical problem in diverting to another near airport in case #2 leads to a closed runway. The emergency could be some pax needing medical assistance, so no risk to the aircraft itself, but a life in danger.

@ricardomenzer If ATC were to wait for the emergency aircraft, how long should they wait for? Suppose there were a medical emergency an hour into an SFO->Hawaii flight and it turns back. Would ATC divert all flights into SFO for the next hour, as one of them could "mess with the runway?" Of course not.

@ZachLipton in a situation where the traffic is away from the airport, I agree with you. Diverting to another airport wouldn't add much in trip time. But in my question, the traffic is already in a (long) final, just some few minutes from touching down. In this case, diverting to another airport would cause a significantly amount of time added to the actual landing.

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text:
What are the issues with building modular aircraft?
This might make sense as

commercial aircraft basic design has remained the same for the last 50 years or so, but materials used have changed
parts such as wings, landing gear, nose, tail, jet engine, fuselage, avionics and seats all come from different specialized manufacturers
so OEMs like Boeing, Airbus, etc., can build modular planes where each of the above mentioned parts should be replaceable with a better upgraded part
and this can prevent wastage

Making those parts modular is hard, e.g. making them field replaceable. But it's feasible to have different parts as options and make different models as different combinations, which should be the current practice already.

Designing "better", upgraded part is a lot of work. And then everything has to be thoroughly tested to work together, which is even more work. That's why aircraft manufacturers usually choose to upgrade as few parts as possible and only those where most significant benefit is expected.
Take for example 737. The type was upgraded with new engines several times, because evolution in engine technology brought significant fuel savings. But the wings only got winglets, which was less work than redesigning the wing. And the fuselage was not changed at all, only it is now built longer by adding some frames.
And the situation with A320 is similar. The "NEO" designation for the new series entering production stands for "new engine option", because that's what the upgrade is about. Beyond new engines and winglets there is basically no other change.
And that was just type changes as in new aircraft being built from upgraded parts. Upgrading an existing airframe is another can of worms.
Basically the joins between airframe components have to be very strong and light. The most common joining method that satisfies this is riveting, with gluing gaining popularity for composites and in some cases welding appears (aluminium is difficult to weld, but friction-stir welding seems to work satisfactorily).
Well, none of these methods allows easy disassembly. To make the components replaceable, they would have to be bolted instead. However, bolts have several major disadvantages. They can shake loose, they don't fit tightly (rivets expand to fit) and they are considerably heavier. These things make them totally unsuitable for the high-stress joining, especially for joining fuselage and wings. And drilling out the rivets and riveting in a replacement is too much work and there is a high risk of damaging the parts, which could easily make them unsafe to use.
And then there is a question of the removed parts. So you replace the wings after half of their life, because new, more efficient model is available. But the old wings could have still generated revenue. By discarding them, you've lost those money. So to pay off, the difference in efficiency must make up for that.
Well, it is extremely unlikely to do so. The new engines of 737MAX or A320NEO save about 15% of fuel, but engines are the component where by far largest benefit could be gained. Redesigning any other component can save at most few percent.
Yes, some airframes did get structural upgrades (upgrading avionics or other small components is of course easier and thus done more often), but usually these were military aircraft where the changes provided some other benefit that was worth the effort.
And some more airframes got refitted to different engines, but engines have shorter life, so they have to be designed to be replaceable. And even there it is usually military aircraft and usually only because the airframes are used much longer. For example KC-135 was reengined, but that was about the time its civilian counterpart, B707, was scrapped altogether.
But most of the time, replacing parts of an aircraft would not prevent any wastage but rather create a lot of it.

Upgrading most of the items listed in the question would be considered a major change, and require approval from regulators. For an example let's just consider wings, nose, tail, engine, and fuselage. That's 5 different major sections of the plane. Even if there are only 2 options for each of those, that creates 32 unique configurations. Even if some of these can be eliminated, this is a lot of configurations. Each one would have to be approved by regulators. The manufacturers would also have to stock parts for the different options, reducing the benefit of designing, manufacturing, and installing a larger number of just one part.
There is good reason for having every major configuration separately certificated. Airplanes, especially airliners, are complex machines, where all of the parts interact in many ways that affect the performance and safety of the aircraft. It takes a lot of analysis and testing to fully understand all of the interactions and ensure the aircraft will perform as expected.
This being said, some options do have enough demand to be offered by manufacturers. Most aircraft have different fuselage options that vary in length, allowing different passenger capacities to match the needs of operators. However, cutting into the fuselage to change this would be much more expensive than just selling the plane and buying the desired size. Many aircraft also offer engine options from different manufacturers. Although compatibility is generally limited to one engine type, engines can be removed with relative ease and performance upgrades can be available. Although avionics are typically standard, there are upgrade options as newer technologies emerge. Seats are already a modular component that can be rearranged and swapped out and are generally chosen by each airline.
Wings must carry the full load of the plane, and often integrate engines, landing gear, and fuel tanks. They tend to be more efficient with a larger span but aircraft are also limited in wing span, so even different sizes of the same type may use the same wings. Adding winglets is an option that requires much less work than replacing the whole wing for a small improvement in performance.
There can be different options associated with landing gear, such as different types of brakes or tire pressure monitoring. Other than that, there aren't many options to be offered. Landing gear does have a hard limit on lifespan though, so it is designed to be replaceable.
The tail tends to be designed and sized to the aircraft, and is critical for aircraft stability and control, so is typically the same across versions of a model.
As far as offering upgrades to major components, the benefits of such an upgrade usually do not outweigh the large costs of offering it.

One example of the complex interactions is that many avionics are based on design of sensors, control surfaces and aerodynamic profile.  Those aren't easy to adjust, test, and update for new configurations, which is one reason why avionics cost so much.  Simple changes like lighter wings or adding a position to make ailerons extend further can create lots of problems and redesign in avionics.

One reason that aircraft aren't modular is that many aspects of aircraft design are done looking at the whole airplane, not just at its parts.  Some examples are:

There are various aerodynamic interactions like center of gravity vs center of pressure, tail lift vs wing lift, lift vs weight, roll-yaw coupling, etc. and these have to be coordinated across the entire aircraft to ensure the aircraft has the desired stability.
Structurally the aircraft needs to be strong enough.  Something as simple as a heavier-than-expected avionics platform can force a redesign of the structure, which may force a redesign of the wings and other parts as well to support the heavier structure.
Safety levels are calculated as the sum of parts, not just for each part individually.  Odds of structural damage depends on more than just a single structural "part", and there are balances between sensor dependability and avionics error checking, control surfaces and backup control surfaces, etc. to achieve desired safety levels.
Aerodynamics, engine response, and structural resonance are used in avionics to ensure the desired performance is achieved.
Avionics is very platform-specific and things like displays have to be programmed specifically for every possible configuration of sensors, control surfaces, pilot controls, radios, etc.
The electrical system needs to be able to provide enough power for everything, possibly over several separate channels for redundancy.
Human factors analysis is usually done as the sum of different interacting parts throughout the cockpit, especially for complicated analysis like determining whether single-pilot operations are possible.

That being said, things that can be added or removed easily like entire avionics platforms, wingtips, seats, or sensors sometimes are, as noted in fooot's answer.  The modularity of an aircraft is more like building and less like a desktop computer.

The centre of gravity of an assembled and loaded plane must be in the right position, relative to the position where the wings are connected.  Fitting a different tail, nosegear, engines would affect the fore and aft position of the cg.
Therefore we would need a fuselage where the wing position could be varied according to the chosen configuration.
Problem: the fuselage needs to be as light as possible in most places, and strengthened in the place where the wings are connected.  So we would end up needing a different fuselage for every configuration.
(There are many other reasons why a totally flexible modular approach is impractical, but I've given the most basic engineering-based one I can think of.)


text:
why does it cost so much just for an hour of training?
I'm currently in the process of becoming a pilot and the question I keep asking myself is why does it cost so much for just one hour?

Are you referring to rental rates or instructor?

Compare costs for running an aircraft with costs for running a car (insurance, fuel, parking, maintenance, vehicle's purchase,...). This is only a part of the answer why it cost more than one hour in a car (to obtain the driving licence).

Possible duplicate of What are the typical facets of ownership costs, for a single engine aircraft?

It's valuable to remember that often times, you get what you pay for. You may shop around and find a cheaper school, but that could be because they're skimping on maintenance or have less experienced CFIs. Just something to bear in mind.

You've not specified how much you consider "so much", however it's unlikely to matter too much to the answer. What you're paying for is (at least) twofold, and probably consists of

The rental of somebody else's aircraft. Every hour you fly this aircraft takes it an hour closer to an expensive maintenance window. There are costs involved in running an aircraft much like there are costs associated with owning/maintaining any vehicle. Also, fuel isn't free - its is often rolled in to the cost of rental for aircraft.
The time of an instructor, who himself has spent time/money learning his craft, and quite possibly does this as his job (as in, its his sole purpose to earn money from teaching you to fly). He has skill and experience, and like all jobs, the more his skill/experience the greater fees he can charge.

You may have missed the first rule of purchasing a service - shop around. Is your flight school/instructor of a comparable price to others in the locality? Is the instructor you're using a senior CFI, or a new CPL hour-building to get a job with an airline? You will potentially get a different level of service depending on price, but this may suit your wallet better while still giving you the skills you need to get your own pilots license.
Anectote: When I was training for my PPL (circa 2001-2002) in the UK I paid roughly £150/hr. This included the hire of a C152 and a pretty experienced instructor. From memory the instructor was £80/hr and the remainder was the aircraft. When I got sick of being cramped in a C152 with another 6'2" guy, I paid more to fly a C172 - probably added about £40/hr to the cost.

Here is a nice answer that covers the various costs of owning an aircraft and will give you a good idea of what goes into it. The only additional thing that a rental plane needs (here in the US under FAA regs) is a 100 hour inspection while private planes only need an annual. Generally speaking rental planes also tend to get fixed pretty quickly as the school does not want or cant afford to have them out of service for very long. Both the flight schools I have been at had their own maintenance hangers and mechanics.
However the costs are quite variable even in a given area. I used to fly out of KPNE and rent a warrior at 130(USD)/Hour wet, that flight school closed and I am now up at KDYL renting the same plane for 108(USD)/Hour wet. Both flight schools charge 40(USD)/Hour for the instructor. Compare this to the other airport in the area Wings Field which has a brand new fleet of Cirrsus' renting for around 300(USD)/Hour wet.
On any note the Flight schools usually have to cover the costs of owning the plane as well as make a profit. Its also wise to work in some flex to that since planes do break and are often costly to fix even the simple things. Flight schools typically also need to cover the costs of owning what ever building they operate out of as well as paying anyone that is not a flight instructor that works there.

I know its implicit that you're in the US, but could you qualify what unit your per hour costs were? Especially if that's 40{llamas} per hour!

USD but ill add it, for some reason the $ makes the text do something funny

@Dave Don't know if you've figured that out, but that's probably Mathjax. You can use \$ to override that and just include a plain old $ sign in the text.

@MichaelKjörling ahhh thats been a headache for me on a few questions ill use it from here on out though, thanks!

Depreciation cost of the aircraft
Planned and unplanned maintenance
Insurance
Organisation fixed and variable costs (offices, admin
personnel, stationery etc)
Aircraft utilisation (hours you can sell vs hours available)
Fuel and oils
Instructor hourly rate
Service fees paid to the local airfield where the aircraft lives
Hangarage
Profit

It's amazing that I can do this locally for about $250 per hour.


text:
How to find trim condition of a sectional airfoil without knowing the angle of attack?
I am using a reflexed airfoil designed for positive pitching moments to achieve a pitching angle matched to the changing of free-stream velocity (Aerodynamically tailored).
I ended up with a pitching moment equation
$$
dM = c*Cm_{a.c} - (C_{l_0}+C_{l_α}*α)*Χ_{a.c}
$$
where $c$ the chord length, $Cm_{a.c}$ the pitching moment coefficient about the aerodynamic center of the airfoil $Cl_0$ the zero lift pitching coefficient, $Cl_a$ the lift coefficient at a certain angle of attack and and $Xa.c$ an offset distance about aerodynamic center.
I want to design a propeller and the data i have is free stream velocity, RPM, and geometry of the blade.
I assume a thin airfoil so the lift coefficient ($(C_{l_0}+C_{l_α}*α)$) is roughly $2π*α$ and $α$ varies with free stream velocity and rotational speed: $α = Δβ - tan^{-1}(V_{inf}/V_r)$ and $Δβ$ the pitch angle.
The idea is to find the ideal angle of attack $α$ that satisfies the pitching moment equilibrium condition $dM = 0$. However, pitching moment coefficient $Cm_{a.c}$ is also unknown.
*Let's say $X_{ac}$ value is given.
So, my question is how this equation can be solved? Can i get any other data from the airfoil's profile that help to find the solution?
Are reflexed airfoils have any characteristics that i should consider in such situation?

I don't understand the chord with the $C_M$, that would make the dimensions not right.

@Koyovis This comes from the equation
$$dM = dM_{ac} - dL*X_{ac} = 1/2ρV^{2}c^{2}Cm_{a.c}dr - 1/2ρV^{2}cC_LX_{ac}dr  = 0$$
$C_L = (C_{l_0}+C_{l_α}∗α)$

Yes indeed. I would expect a length divided by a length, a dimensionless entity, to accompany the $C_M$

@Koyovis Imagine schematic shown in this link: https://aviation.stackexchange.com/questions/40910/how-to-define-pitch-angle-for-a-passive-variable-pitch-propeller?noredirect=1#comment106318_40910

Do you want to solve the equation for $Cm_{ac}$ or for $\alpha$? If you have one equation you cannot solve for both. From the title of your question it appears that $\alpha$ is an unknown, however if free stream velocity, rotational speed and twist are known,  then $\alpha$ is known and you can solve for $Cm_{ac}$

@Koyovis the two variables depend on each other..and if i find one...other can be found from the polars of the airfoil. But, how α can be found by knowing only freestream velocity and rotational speed? Let's say there is no twist at the moment so angle of twist = 0

If you have access to a model of your airfoil, a moment balance, and a wind tunnel, you may determine $C_{M_{ac}}$ experimentally: the moment the wing experience may be normalized to calculate $C_{M_{ac}}$
Then solving for alpha is trivial. Otherwise a tool like XFLR5 may be useful to find  $C_{M_{ac}}$ for your airfoil.

I believe he's using a symmetrical aerofoil and a NACA profile of which data is published.

@Koyovis I am using a an EPPLER airfoil with reflexed profile. For symmetrical airfoils i found that pitching moment coefficient is zero, so it doesn't work

If it is published the pitching moment at ac is usually published

@user74671 Yes. It is published, but the only thing i can find is a relation between $Cm$ and $α$. http://airfoiltools.com/airfoil/details?airfoil=e328-il (last plot)
*Pitching moment has to be zero for static stability

Ok then still find alpha where L=0, look at graph, Cm there is Cm at ac

with L you mean lift? If so, why am i looking for L=0?

If you look at your equation in your other question the over all moment coefficient is made up of CMac, and the moment produced by the lift. (Drag would also produce a moment but its small). When L (or CL) is zero, the only moment acting on the foil is that at the aerodynamic center

The problem is that L (or CL) varies with the freestream velocity. So i suppose that it cannot be zero at any speed condition. However, my idea is similar; to give an initial value to CL and then find corresponding coefficients and α. But, is there any value can be used as Cl starting point for small propellers (≈15 cm radius)?

Cl varies with alpha. It can also vary at different reynolds numbers. Choose the reynolds bumber you anticipate it to operate at then look up alpha when cl is 0

@user74671 Ok, thanks..So alpha will be kept constant at any speed condition and is the pitch angle (Δβ) that will change throughout a range of speeds right?

Sorry i was speaking in a general airfoil sense. I believe i mean pitch angle. I mean the angle of attack of your airfoil on the propeller with the air. It is a little more complicated with a propeller since there is relative velocities between the spinning and the free stream velocity

Yes, as i mentioned before, angle of attack depends on pitch angle minus the inflow angle: $α=Δβ−tan^{−1}(Vinf/Vr)$. So α will be constant..and Δβ will change according to Vinf and Vr. Is that what you meant?

I think considering the pitch angle and relative velocities is unnecessary to find the cmac For the airfoil.  At first just consider the airfoil in a 2d sense. You will need to figure out the range of Re #s that it will experience by determining the range of velocities it will see


text:
Does drag increase with increasing bypass ratio in turbofan engines?
Does drag increase as the bypass ratio increases in turbofan engines? Is there an analytical expression describing the increase in drag related to an increase in the fan duct diameter? How else might one consider this effect?

To me the bypass path seems to be a lower drag path than it would if it were going through the compressor, so it would (maybe I'm completely wrong) that increasing the bypass ratio wouldn't increase the drag vs the same size duct and a lower bypass ratio.

According to this 1975 NASA report on the effects of turbofan engine bypass ratio, the drag does increase for increasing bypass ratios. In the report, they use the following drag coefficient equation:
$$
C_{D,prop}=C_{D,nacelle}\cdot \frac{A_{nacelle}}{S} = \frac{D_{nacelle}}{\rho_\infty A_{nacelle}} \cdot \frac{A_{nacelle}}{S}
$$
As shown below, the nacelle drag coefficient initially increases for increasing bypass ratio.

Since $\frac{A_{nacelle}}{S}$ also increases with bypass ratio, the propulsion system drag will increase as well. So drag is closely related to the frontal area of the engine.

(images taken from report linked above)


text:
How could "aggressor" pilots fly foreign aircraft without speaking the language?
Context
I watched a couple documentaries recently and found one where they were mentioning the training of American forces against Mi-24 that were captured and brought back to the US to test fly them. Shortly afterward General Chuck Yeager tweeted a quote from General Boyd saying

Because of Yeager, we now know more about the MiG-15 than the Russians do.

after he flew one in 1953 that was captured during the Korean War.
Research
This piqued my curiosity because as far as I know Russian aircraft have:

Different units for instruments (metric system with km/h, meters etc.)
Different approach to instruments (as explained in this question)
Obviously, everything written in Cyrillic with alerts in Russian

I checked the page on Constant Peg program in the US to train aggressors and them flying foreign aircraft (like MiG 17, 21 and 23) as well as other aircraft. While I understand that this specific program is still classified, there are other occurrences of aircraft flown by "non-Russian speakers" or at least non-Natives.
While it is totally possible that General Chuck Yeager is fluent in Russian, I have some doubts about flying an aircraft where everything is written in another language from the fuel dump to the auto-pilot settings, and be able to operate it easily (on top of that without a manual).
Question
Now this led me to this question, how do you fly an aircraft without speaking the language and how do you read the instruments and their functions ?
I very much doubt that they just put sticky notes over all instrument panels with the label of instruments (but I could be wrong, who knows).

It isn't like they jumped into the MiG and took it for a ride without any training. There was probably a team of people (who fluently spoke Russian) that translated the documents (or pilot information) and gave that information to the American pilots to fly it. They got training on the instruments before going up so they knew what they were looking at, even if they couldn't read it.

He did say to check his autobiography to someone who asked for details.

Actually, they did just put labels on things.  That plus the Korean pilot using hand motions to communicate the idea of a spin urgently followed by ones indicating ejecting.  It's also not unlikely evaluation flights would be accompanied by a cooperating pilot in a plane with familiar instrumentation (and given the desire to measure performance, instrumentation of recent and known calibration).

Chuck Yeager wasn't just your average fighter pilot.

"I could be wrong" -- sticky notes weren't invented until 1968, so I think you're not wrong to doubt that they used them during flight tests that occurred a decade or more earlier. :P

It is easy to recognize most of the instruments. Many even for a non-pilot enthuziast. I'd be more concerned about the different way the eastern artifficial horizons work.

This is based more on DCS (which is a "study sim") than actual experience, but airframe-to-airframe idiosyncracies among American aircraft can be a bigger difference than moving from American to Russian.  The F-14 flies more similarly to the MiG-21 (high power interceptors!) than it does the A-10 (put the throttles at 100% and chug your way to where something needs loitered around).

@ErinAnne I doubt F-14 has such a deadly tendency to get into the second flight regime as Mig-21. Are you sure that the game simulates that?

US and Russian planes at least have a great deal of things in common, since they can both be traced back to common ancestors (you might have to go pretty far back, but there have got to be some commonalities).  Now, Will Smith being able to competently fly an alien spacecraft in Independence Day - that stretches credibility, but hey, fiction...

Before "sticky notes" there were DYMO plastic tape labelers!

Even if you understand Russian and lot of thing are similar, there are some important differences like Attitude Indicators

If the other answers would not work, it would be plausible to mandate that these test pilots learn Russian, after all astronauts going to ISS (and astronaut candidates that didn't go) were required to learn Russian.

@MarkStewart and before those there was painter's tape. Paper tape you can write on. Heck, it's still used today.

@DarrelHoffman I seem to remember John Rambo being able to fly a Russian Hind gunship without too much preparation in Rambo III.

A couple of things come to mind that enable this:

you don't become a fighter pilot if you are not intelligent and highly motivated
you are not learning a new skill, just doing what you are already trained to do in an environment that just looks different (this would somewhat exclude Russian helicopters)
the list of things to learn is really not that long, I'm taking the liberty to throw in a guess of 100 items
you have a huge organization backing you up (translations as mentioned in comments, intelligence data etc.)

So: You are a person that is able to fly fighter jets, most probably you are damn good at it if you are given the opportunity to fly a fighter caught from the enemy.
You learn new stuff easily, and you are thrilled to do this, which of course helps in the learning process. Your organization provides you with pretty much every bit of information about the task you are about to undertake, translated manuals etc.
Regarding the cockpit language barrier, it's not that hard to learn the labels on switches and gauges. For example the picture in the question: I took a not-so-wild guess that it's an altimeter, checked with translator and yes: высота is altitude in English (pronounced something like vysota but that really doesn't matter). From now on, when I see text that says высота, I know it means altitude. On Russian planes the pilot just has to remember the altitude is in meters, but since the label looks "weird" I don't think there's much chance of a mix-up.
Anyways, when operating a fighter jet, you learn the location and operation of the critical switches and systems by heart, you do not browse around the cockpit searching for switches when you need to do something.
Once you've become familiar with the user interface, the basic flying will be pretty much the same as in any western fighter.
P.S. There's one thing that really helps: Cyrillic numbers are not used anymore :)
P.P.S. this short film on Air&Space Magazine website tells very nicely and in a compact package of the findings made by Chuck Yager (Major at the time) and General Albert Boyd during test flights of the MiG-15. Thorough testing gave USAF critical information of the capabilities and weaknesses of the enemy fighter, giving them strategic and operational advantage.

Sounds very reasonable to me (+1) and is exactly what I assumed. But that exclusion of Russian helicopters made me curious. Are they completely different or rather almost similar to western helicopters?

Thanks that is what I was looking for, and indeed, numbers in cyrillic are... Well the same

@PerlDuck the Ruskie choppers main rotors rotate in the opposite direction compared to most western ones.

And for the things where the labels actually matter (circuit breaker panels -- not something that lends itself well to brute force memorization), the low-tech but effective label-maker probably works just fine.  Or, if really necessary, fabricate a new face for the particular instruments -- although I doubt that's actually ever needed.

Not just fighter jets, you learn the location of instruments & switches you need even in a GA plane.  (Or at least I do :-))  FTM, if you're flying VFR in uncontrolled airspace, just how much actual need do you have for the instruments, anyway?

@jamesqf true about GA and knowing your switches, one should at least know the aproximate location ;) seriously speaking, even in GA you should find certain things immediately without looking: battery, ingnition, everything about fuel etc. Regarding VFR: you should always know your speed and altitude, be it in english or russian :D

@Jpe61: I disagree, at least WRT getting that info from instruments in a GA plane.  (Never flown fighter jets, so I can't really comment.)  One can get altitude from looking out the window, speed from how the plane feels and sounds.  Of course this isn't precise, but it would be enough to fly the plane if you had to, e.g. if someone has sabotaged all your instruments.

@jamesqf yes, you can operate an aircraft you know without gauges pretty safely in VFR, but when it comes to rules and regulations, you are not allowed to, see ICAO annex 6, part I, chapter 6, section 6.4, for example. Flying a fighter jet in combat training, you'd want to know your speed not to fly outside the envelope.

Knowing that the picture was of a Russian aircraft instrument, even my untrained self pretty quickly thought "altimeter," what with the general shape and markings, the "mm" indicator and dial no doubt for that air-pressure-at-ground-level thing altimeters need, and especially a marking that looks remarkably like the word "meter" even if you don't know that Russian/Cyrillic "Р" approximates a western "R."

https://en.wikipedia.org/wiki/Cyrillic_numerals exists. They just aren't used anymore.

Whoa, thanks @Mołot, I had no idea, I'll update my answer.

@Jpe61: But I'm not talking about flying in combat training, I'm talking about the test pilots who first get their hands on the new MiG-whatever, in order to determine just what the "envelope" happens to be.  Then you can replace Cyrillic gauges with English ones, or just use a label maker..

"now when I see text that says высота, I know it means altitude" I rather doubt that if you had five similar cyrilic words you'd really remember the exact notation for "altitude". Well you might have an eidetic memory, but at least the vast majority of people wouldn't. But then it's not necessary anyhow: I doubt that any pilot ever had to read "altimeter" to find the correct instrument, or that you would have enough time during a flight to start reading labels. It's all muscle memory.

@Voo a single word might be difficult to recognize from "a lineup" of five similar ones by an average person, but I stand by my claim that fighter pilots are well above average when it comes to intelligence, and test pilots profoundly so. I do completely agree with you on that it's not necessary (at all) to be able to read labels as long as you know where what you need is and how it works.

this. The main difference is that things are labeled in metric instead of imperial.

@Voo I disagree. It's not at all hard to learn to read Cyrillic phonetically (as in, it'll take you a couple of hours) and, at that point, it's no harder to learn a short list of Russian words than, say, a short list of Portuguese or Dutch words. But this is where I do disagree with something in the question: to me, the pronunciation (even if it's not accurate) is important. It's much easier to remember the sound of a word than some sequence of abstract symbols.

Ok, I'm Russian, so let me speak from the "aggressors" side. The language barrier is not a big problem as was mentioned. The real problem is the measurement system differs from your brain, reflexes and perception systems are used to. It's not enough to perfectly know that 1 meter = 3.3 feet, you need to feel this intuitively. Living with a "foreign" measurement system for decades, most people still convert values into the system they grow up with, and this conversion takes some seconds, which might be critical when you flying on a jet with gauges, graduated in a foreign measurement system.

You don't need to speak(1) fluent(2) Russian(3):

In fact you don't need to speak at all, just understand.
You don't need to be fluent, just understand enough to not crash the plane.
It's not about Russian, it is about Russian Aviation Jargon. (Think about English: if you walked up to a random person on the street and started talking about laminar flow, elevons, flaperons, flat spins, etc., then from their perspective, you might just as well speak Russian!) We are talking about a couple of dozen terms at most, and highly standardized technical terms at that. Also, physics and aerodynamics work the same everywhere, so there are going to be a lot less cultural differences and a lot more straightforward 1:1 translation.

Last, but certainly not least: we are talking about trained and experienced test pilots. It is literally their job to fly airplanes they don't know how they will behave, and figure it out as they go along.

This is so true.  I speak effectively no Japanese, but I'm perfectly capable of having reasonably lucid conversations in little more than totally broken jargon with Japanese engineers working on niche industrial/scientific equipment that we're both experts in.  We can barely say more than "hello" to each other otherwise, but if it's troubleshooting a torque overload on a servo motor, or tracing down an aberrent interlock in PLC ladder logic we basically speak the same language - jargon.

@J...: Indeed, it has happened to me more than once that our customers discussed some technical detail amongst themselves and then wanted to explain their conclusion to me, only to find much to their (and my own!) surprise that I actually understood them. This has happened to me in Norwegian, French, Spanish, Portuguese, Catalan, Dutch, Flemish, and Polish, none of which I speak fluently. (In fact, the only one of those languages I learned at all is French, which I learned 5 years in school, but haven't used in 23 years.)

@J...: Conversely, I do read, write, understand, and speak English fluently, but I have no idea what you are talking about. (Well, that's an overstatement. I have a rough idea what PLC ladder logic is, but I wouldn't be able to converse about it.)

Just to add: I was at an airshow in Australia once in the 90's and the radio announcer said the MiG-15 which was flying had labels on all the instruments to meet the CASA (Civil Australian Safety Authority) regulations to be allowed to be registered here. Sure enough, all the instruments had sticky-back DYMO labels (the old style, with the white stamped/embossed lettering on the coloured plastic strips). This is just what I remember him saying: I wouldn't vouch for it being part of the regulations as that's getting off-topic.
I can't guarantee it's the same aircraft I remember seeing, but this is exactly what I mean:

Addition: In the cold war era, quite a lot of documentation for Russian equipment seems to have been available (well, existent) in German too (eg you can find training films for setting up antiaircraft batteries on youtube, in German), plus some export versions of Russian-made gear with German labelling. The reason is that the Nationale Volksarmee in East Germany was supplied with various Russian equipment, and obviously needed to be able to operate it.
This extends the circle of people who can help - also, there were friendly ties with the West German Bundeswehr (who did not use Russian equipment but could certainly help with anything labelled in German).

Good point, and welcome to Av.SE!  After all, some of the aircraft that ended up as Constant Peg jets came not from defecting Soviet pilots but from pilots of other countries where they'd been exported.  Those countries would be sources of the same sorts of things (in languages beyond Russian) you mention.

My guess is that all Eastern Bloc pilots were required to know Russian though, it was taught in schools and to officers.

BTW, there were a few MiGs gifted to the Bundeswehr after the wall fell, however they were gifted on to Poland several years later....

As a non-native speaker for both English and Russian I can confirm that you don't really have to speak (or even read) some language in order to operate a more or less familiar machine labeled in that language.
Most people from smaller nations are used to this, those that were young in 1953 - even more so.

In this part of his TED talk, Col. Chris Hadfield recounts his return from the ISS in the Soyuz spacecraft.
His speech is about how the experience could have been scary and overwhelming, but

"instead, twenty years previously, we had started studying Russian. And then once you learn Russian then we learned orbital mechanics in Russian, and then we learned vehicle control theory, and then we got into the simulator and practiced over and over and over again"

This is a slightly different situation since it was a collaboration between Russia and NASA, but it goes to show that pilots can learn to fly pretty much anything with instruments labelled in any language.

It's not that hard to learn a language, certainly the technical parts.  However it's a bit more than words; for instance Soviet attitude indicators work very differently.
You just need to think in Russian :)

Are you sure that those word in the video: ruž'e, pripacy, orudie, charjady, vcpyška, komki... are meant to mean anything?

@Harper this would deserve +2 simply because Clint Eastwood!

@VladimirF In fact, they don't :) Rifle (specifically, hand rifle), ammunition (боеприпасы actually), cannon (not exactly the right word, but possible), shells (as in cannon shells), flash (not sure what it means here), lumps (no clue whatsoever)

That would not be required as an experienced pilot can find their way around the cockpit with relative ease.  You can spot the basic flight instruments, navigation instruments and engine instruments with ease.  Additional systems can be re-placarded as well by native language speakers.  In addition most of these ‘acquisitions’ were turned over by defecting pilots who are generally happy to brief our test pilots on the system functions in question prior to flight.  If you were a test pilot selected to be part of constant peg or similar reverse engineer program, you would receive quite a lot of briefings from the intelligence community and technicians who have worked on that aircraft prior to ever getting in and flying it. You will be fairly well-versed in the systems and their operation prior to your first flight.

I'm not a pilot or aviation expert but I think one point is missing.
I think the majority of aircraft are designed to operate on ground without actually flying.
That's because to make pre checks. It would be easily fatal if you need to check a critical system mid air to find out it's failing.
Thus you can try out all basic systems to fly on ground in safety and without time pressure.
After you figured that out you can at least fly by manual systems. Which likely most aircraft have as well as backup.
Don't you think?

I'm wondering who and why the downvote? Because @steros made a perfectly good and accurate point here. That is how anyone who is about to start flying an unfamiliar aircraft begins: an hour after hour, sitting in the cockpit running through switches and procedures.

It is not the gauges that are the problem.
Think of it as something you might be more familiar with, like a car from the 1950's
As long as you are traveling during the day and paying attention to the vehicle, they gauges don't really tell you anything you can't estimate on your own. They just give a bit more detail.
It is the switches that are difficult.  Have you ever driven an unfamiliar car, and accidently turned on the windshield wipers?  Same thing here.  You need to know what switches do what, you can figure that out when your not moving, and re-label or memorize.

I don’t understand the difficulty here. Why would it have been difficult to learn just enough Russian. You wouldn’t have to know it fluently. You are not having a conversation on aerodynamics with the plane.
As far as the differences in the gauges, it would’ve been no different than transitioning from steam to glass cockpits now. Things look different and there may be a different perspective. Any pilot who learned the complexities of aircraft in general should be able to be trained on those differences.
It’s like an American driving a 15 passenger, manual transmission, right-steering van or truck through the London congestion zones. Or, driving through a non-English speaking country. You just adjust.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

authors: Vladimir F Героям слава


text:
What is the name of this airfoil?
Is there a general name for this type of airfoil? I'm having trouble finding any information on it so if anyone knows anything about it please let me know!

As the caption says: It is a reflex airfoil.

That's a reflexed trailing edge airfoil. Its center of pressure moves forward with decreasing AOA giving it an almost constant pitching moment. It is often used for flying wings.


text:
Can foreign pilots get a Canadian ATPL and work for a Canadian commercial airline?
Can foreign pilots get a work permit for a Canadian commercial airline upon the completion of their training in Canada?

It is certainly possible that anyone might get a work permit to do any work in Canada. Are you asking if there is some automatic grant of a work permit?

@DJClayworth I am asking specifically for "airline pilots" to work as an airline pilot upon getting my licenses and 1500 flight hours, what I mean is practically speaking why would an airline sponser a foregin pilot and cost itself time and money while they can hire Canadian citizens or permanent residents?

Because after some research i found out that H1B visa (work permit in the USA) is difficult to get, so i wanted to know what is the situation in Canada for hiring foregin pilots in terms of ease/possibility

There is a whole site called Expatriates which is all about living and working abroad.

What licenses do you already hold?

None, I am still in choosing a flight school phase, planned start date march 18'


text:
The F16 stick movement is little. But how?
The F16 stick movement is very little, is 1/8inch. So there is just a stop point at the end of the movement, or the stick is  hard all the time, but move  a bit ? There is increase in stiffness to apply  full displacing of the stick?

I don't know the exact answer (would like to know myself), but given that the F-16 stick senses the force rather than movement, it doesn't matter too much. The movement, whatever it is, is just for the pilot, i.e. ergonomics.


text:
In symmetrical airfoils is the stall angle the same for negative AOAs as for positive ones?
In symmetrical airfoils is the stall angle the same for negative Gs as for positive ones? Let say the stall angle is 17 degrees AOA. Is it the same if you push the nose down?

Have you seen this answer? I think it already answers your question. If not, feel free to clarify what is missing...

Now I seen your post.

As Bob Hoover famously said, an airplane only cares about airspeed to fly. Whether it is upside down or not don't means anything for the flight characteristics. For a symmetrical airfoil what is the difference between - 1000N of lift and +1000N of lift? You just reverse the succion-pressure side and voilà you have the same situation and thus the same behavior.


text:
Why the European Eurofighter Typhoon did not have pitot tube in front of the radome?
The layout of the aircraft does not have the proper pitot tube. I believe that the aircraft needs clean airflow for its instruments .

To my knowledge, on most airliners the pitot tube is in line with the flight deck, well aft of the nose and radome. On smaller aircraft the pitot tube may be mounted on the wing. Why do you believe it should be placed at the very front of the aircraft?

Does this answer your question? How are IAS to CAS conversions calculated?

The aircraft doesn't "need" it. The engineers may want it, but like everything, this is a compromise, and there are workarounds.

Putting anything made of metal in front of the radar antenna housing will put a blind spot in the radar's beam. There are plenty of other places on an airframe to obtain useful pitot readings beside the tip of the nose.


text:
Why are true headings followed above 73N in the northern hemisphere, whereas in the southern hemisphere the change is made at 60S?
The question is in regards to the asymmetry of the changeover latitudes and NOT about why it needs to be changed.

Southern tip of South America is about 60S

@expeditedescent I made that observation as well, but it doesn't seem like a consistent reason as the highest northern land mass extends to 83N.

Because there’s a lot more airports between 60N and 73N than between 60S and 73S?

At 65°S, wouldn't the pole be on the wrong side for certain longitudes? (as the South pole is at 64°S lat.).

Earth's magnetic field is not symmetric north to south.  In particular,  the magnetic declination can get significantly larger at a given southern latitude than it does at the corresponding northern latitude.  This can be seen by looking at a world declination map:

Curves of a given declination reach much lower southern latitudes than they do northern latitudes.  For example, the highlighted curve is 40° west of north declination;  its southernmost point in the northern hemisphere is at about 75°N, but its northernmost point in the southern hemisphere is at 35°S (!).  Another way this manifests is that the South Magnetic Pole is at a significantly lower latitude than the North Magnetic Pole (~65°S vs. ~85°N).
As to why the Earth's magnetic field is so asymmetric, that's a question for Earth Science.SE.  My understanding is that you may not get a good answer over there either;  the behavior of Earth's magnetic field is complex and not fully understood.


text:
Are there multiple reasons for the decrease in pressure over a wing?
I'm aware that the decrease in pressure over the wing is due to the curvature of the airfoil which causes a pressure loss due to the spreading of the air as it is redirected.
But is it also due to the increase in velocity from the squeezing of the streamlines at the leading edge, like in a converging duct there is no redirection of flow but there is still a decrease in pressure where there is an increase in velocity?
Is this down to a reduction in the number of collisions per unit time?

You might want to look at this to get a satisfactory answer to how the lift is generated: https://en.wikipedia.org/wiki/Kutta%E2%80%93Joukowski_theorem

There are multiple explanations, but only one reason.

In the same vein, "a reduction in the number of collisions per unit time" IS a "decrease in pressure".

i have heard that the increase in speed reducing the number of collisions is a misconception because as soon as one particle moves on it is immediately replaced by another so the collisions per unit time do not change. Is that actually the case?

It's the Lift Demons

The laws of physics don't work in isolation. They always apply all at the same time¹.
Most of them don't describe causality, but relations that are known to be always satisfied². If you know the speed increased, you can conclude the pressure decreased, but if you know pressure decreased, you can similarly conclude the speed increased. Neither is the reason for the other, rather the properties of fluids are reason both always happen together.
And last but not least the laws of physics as we normally use them are not fundamental, but are various perspectives on the underlying properties of the universe and as such have a lot of overlap. Therefore you can usually arrive at the same conclusions in many different ways (provided you properly account for approximations involved).
In this case, the air following the surface of the wing, pressure dropping, the flow accelerating and the streamlines squeezing are all aspects of the one behaviour of fluids—for which there is no simpler way to quantify than calculating the full set of Navier–Stokes equations (there are some simpler models like Kutta–Joukowski theorem, but can't start from the wing shape, but need some experimentally-determined characteristic values of it).
On the low level, pressure is the total momentum imparted by the collisions per unit time and area. So obviously if lower pressure is seen, the collisions must be fewer or weaker. In practice they are both³. However, there is no simple explanation for it on the molecular level either. It is a result of the complex dynamics that averages out to the Navier–Stokes equation on the macroscopic level.

¹ School lessons often fail to teach this by discussing each in isolation and never synthesizing. However, lift is surprisingly complex phenomenon, which requires applying many of them to model.
² Well, at least not observed not to be satisfied, because positive proofs are not possible.
³ The enthalpy decreases, which means the particles move slower and that means they hit both less often, and with less force. The density also decreases a bit, so there is a bit fewer of them per unit volume too. However, this is all easiest to derive from the macroscopic thermodynamic laws. We do have microscopic explanations for them now, but trying to compute anything directly at the low level is futile due to the vast numbers of particles involved.


text:
Can I get a medical after having had a seizure eight years ago?
In 2010 I had a seizure (as of this writing that would be 8 years ago.)
I was a CFI/Commercial Multi pilot, and the FAA took away my medical. I have never piloted since, though I've missed it tremendously.
At the time I was told that I could not obtain a medical again unless it was after 6 years being seizure free with 2 off medication. I have been off medication for 1 year and have had no problems.
I recently got a battery of tests (EKG, MRI, CAT Scan/CT Scan) etc and found no seizure activity.
Have the rules changed in nearly a decade for this? Should I see an AME or would it be a waste of time? I know there is a pilot shortage now, so I'm wondering if it has gotten more lenient.

What kind of flying do you want to do? CFI? ATP? The rules have not really changed for Class-1/Class-2 medicals, Class-3 went through an overhaul with BasicMed, but it wouldn't affect you unless you wanted to be a CFI.

This is something only an authorized AME can answer for you and it there is no harm in talking to one or two of them. You can find a little bit of info here and a copy of the seizure questionnaire here but that appears to be something an AME would fill out so its contents are not really useful on its own.

At the time I was told that I could not obtain a medical again unless
  it was after 6 years being seizure free with 2 off medication. I have
  been off medication for 1 year and have had no problems.

If you were explicitly told this when the FAA pulled your medical then you still have another year to go at which time you can reapply for a medical.
In terms of regulations §67.401 Special issuance of medical certificates allows the FAA to issue medical certificates to airmen who can demonstrate "a Statement of Demonstrated Ability (SODA)" which is at the discretion of the flight surgeon. In short the regulation reads, if you can show that you are fit to fly and we agree we can issue a medical as we see fit.
What has changed quite a bit is the big overhaul that included the Basic Med requirements which do include some notes on special issuance cases that you may be able to operate under.
For you it also depends on what kind of operations you want to do since you are a CFI/Commercial. If you just want to get back in the air it may be a bit easier to do that.
From what I can tell it looks like you can get it back but you will need to talk to an AME.

Check your seizure from here : https://www.icao.int/publications/Documents/8984_cons_en.pdf
It will at least give you an idea about your situation.
I guess that your seizure is caused by your heart (According to the scans they have asked). If it is neurological, situation changes completely.

Seizures doesn't appear in the FAA list of special issuance conditions for Cat 1 so you may be out of luck.
https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/special_iss/all_classes/
But I would write to an AME anyway.  Nothing to lose.
In Canada the authorities seem to be somewhat more lenient on medical conditioins. Transport Canada has recently issued Cat 1s to a few airline pilots with Type 1 insulin dependent diabetes (albiet with tight restrictions and monitoring requirements).

I’d suggest you talk that one over with an AME and we what they have to say.  It may be a lengthy process but it can be done.  I’d also suggest, if you can, make contact with John King of King Schools in San Diego.  He had his medical temporarily revoked but managed to get it reinstated after having a seizure.  He could also shed some light on the process you’ll face.


text:
Why do we not see propellers on swept wings or jet engines on straight wings?
Why are these configurations not observed often?
The only time I see propellers are on straight wings or on the nose, while jet engines are always on swept wings or the tail. Why?

Welcome to SE... As a new member I suggest you reword your question or narrow the scope of the question or you will see it soon closed. Neither assumption is true - for example consider pusher propeller airplanes and the A-10 Warthog ground attack fighter, L-39, or T-33 trainer.

You can find propellers on swept wing aircraft, such as the TU-95, or more recently, the Airbus A400M.
One turbofan powered aircraft that has straight wings is the Cessna Citation
No, it's not common, due largely to the speed at which the aircraft normally operates. Turboprops tend to operate at a lower speed than turbojets or turbofans, where the benefits of swept wings (better performance when approaching Mach 1) aren't evident, while the benefits of straight wings (better performance at lower speeds) comes in handy on the shorter airfields that smaller turboprops operate from. Bump the cruising speed up to Mach .8+, and the swept wing is the optimal design.
In the case of both the TU95 and A400M, they cruise at higher speeds than most turboprop aircraft, hence the employment of a  sweep to the wings.

"You always see" is perhaps due to you not seeing a wide enough variety of airplanes.  For instance, here's an example of a plane that has both props and jets on a moderately-swept wing: https://en.wikipedia.org/wiki/Convair_B-36_Peacemaker  Here are a couple of other examples (of many) of jets with straight wings: https://theaviationist.com/2014/06/17/scorpion-new-livery/ https://en.wikipedia.org/wiki/Lockheed_F-104_Starfighter
@John K's answer covers the technical reasons for swept wings.  There's also another factor that I'd think is pretty obvious:  if you put props on steeply-swept wings, you need to get the prop far enough out in front of the wing so that it doesn't hit it, which creates structural problem.  But here's an example of a single-engine propellor plane with swept wings: http://thanlont.blogspot.com/2011/04/bell-l-39-wing-sweep-evaluation.html  Then there's the Beechcraft Starship, which has part of the wing swept: https://en.wikipedia.org/wiki/Beechcraft_Starship  (Note the pusher propellors: it's hard to see how tractor props could be mounted on the same wing.)
Many more examples of both sorts can be found by spending a few minutes with a search engine.

Better example of a straight wing jet is the F-84 Thunderstreak or the Gloster Meteor.

Swept wings are for cruising close to the speed of sound (all the sweep does is make the effective chord of the airfoil longer so it's ratio of chord to thickness is higher - a finer profile you might say - and this delays the shock wave formation a little bit).
Propeller tips become supersonic way below the speed that wings start to become transonic, limiting the forward speed the propeller can operate at, so you simply can't go fast enough with a propeller to enjoy a significant benefit from wing sweep.  The Russians did the sweep+propellers thing with airplanes like the TU-95, but in the West it wasn't considered worth the trouble.
So in a nutshell: Tubojets/turbofans go on the wings and tail/fuselage because that's the most efficient place for them, and they're associated with swept wings because they can operate fast enough to benefit from sweep; propellers are on the wings and nose because that's the most efficient place for them, and the wings are straight because there's no point in sweeping them (and dealing with the downsides of sweep) when the prop can't go fast enough for it to be worthwhile.

What about the F-14 Tom Cat that has jet engines with straight wings which can be swept back in mid-air? I understand the bit about efficiency and drag, but what exactly is the benefit of having this "switchable" wing type? Is it just to conserve fuel?

@Samid, that is a question on its own. You can ask it separately, but I'm sure you'll find a ready answer if you search. (Such design is called "variable sweep"). Very basically, remember that aircraft sometimes need to fly fast, and sometimes slow (e.g. for landing)...

@Samid One design purpose for the Tomcat's sweep is to land on the aircraft carrier at a slower approach speed.  (which was a very desirable design feature at the time).

Propellers are more efficient, but they only work well when their tip speed is still subsonic, which limits the maximum speed of propeller-driven planes.
Jet engines on the other hand are inefficient at low speed, but their efficiency increases at higher speeds, and they can be designed for much higher flight speeds.
Straight wing is more efficient, but once the flow over it exceeds speed of sound—and the increase in speed over the wing means it happens about M0.70–0.75 (70–75% of speed of sound)—its drag increases significantly.
Swept wing delays this effect, because only the component of airflow velocity perpendicular to the wing causes it. That way swept wings remain efficient near, and if sufficiently swept even above, speed of sound.
Therefore the slower aircraft have propellers and straight wings and the faster ones have jet engines and swept wings, while the other two combinations don't make much sense.
Note that there are a few aircraft with jet engines and straight wings, either because they are not yet fast enough to need swept wings (e.g. the Cessna Citation I and II or the early fighters) or because they have supersonic wings (e.g. the F-104). And the fastest propeller-driven planes do have (moderately) swept wings (e.g. the Tu-95).

Thanks for explaining. I know there's a few examples but do these configurations confer any advantage, i.e. swept wings on Tu-95? Basically what I'm asking is, why do they bother with these configurations when they know props are better suited on straight wings and jets on swept wings?

@Samid, sometimes you just can't do (or know) better. Tu-95, for example, was built at a time when jet engines were not mature yet, and Tupolev deemed them particularly unsuitable for a long-range aircraft because they were so thirsty. Yet the bomber had to be fast, at least in its maximum speed, so it was designed as such, including a swept wing. And it had to be built NOW, being at the peak of the Cold War: no time to wait for new engines. (At the same time, Americans put 8 jet engines on their new B-52, and the history has shown it was worth the risk).

@Zeus: But the Americans probably had better jet engines than the Soviets.

@jamesqf, quite possibly (although early practical Soviet engines were replicas and modifications of the good British ones). But still, for everyone, after WWII, props were a mature technology, whereas jets were new. (BTW, J57 was a development of a turboprop).


text:
Do I need to obtain a student pilot certificate to transition from Glider to Sport Pilot?
I am a current Private Pilot Glider, and will soon begin training to obtain my Sport Pilot Licence. My question is about the requirement to obtain a student pilot certificate to solo in the training aircraft. I have heard that it is no longer the normal practice to record the solo endorsement on the student pilot certificate, but instead to record it in the logbook.
With that in mind and the fact that I already hold a Glider licence, do I need to obtain a student pilot certificate?

You can't get another student certificate because as a Private Pilot you don't need one (and can't get one). Rather, you're a Private Pilot adding to your existing certificate.
Private pilots already have sport privileges, but if the LSA is a new category/class for you then you still need an endorsement for it. The requirements are in 14 CFR 61.303 (and see AOPA's guide too). You can check the table yourself, but let's assume you're a Private Pilot and you have no medical but you do have a US driver's license. That means the sixth row in the table applies to you:

You must hold the endorsements required in 61.321 for the LSA's category and class
You must comply with the limitations in 61.315, except 61.315(c)(14) and, if a private pilot or higher, 61.315(c)(7)

61.321 requires a logbook endorsement from an instructor who's trained you in the areas listed in 61.309 and 61.311; a proficiency check from a different instructor; an application to the FAA; and a logbook endorsement from the check instructor. You also need a certain number of hours, depending on the category/class of the LSA; see 61.313.
I assume your glider experience already covers a lot of the knowledge and experience required, but your sport instructor will have to determine exactly what training you still need.
(This appears to be the opposite of this question, by the way.)

Do you need to take a new Knowledge test for the new category?  I know you need to do a check-ride for the new category but not sure about the knowledge test.

@DLH I don't know much about sport pilot, but there's no knowledge test and the practical is a proficiency check, not a checkride. That means, an instructor can do it, you don't need a DPE or FAA Examiner.


text:
How is proper CG maintained in ultralight pusher aircraft?
Considering pilot weight can vary 100lbs or more how do ultralight pusher airplanes maintain proper CG range?

Usually with suitably-placed counterweights. I used to fly a two-place pusher Chickinox kot-kot that, to be flown alone, needed a lead counterweight of about 15kg fastened on the extreme nose.


text:
Are there regulatory bodies for investigating UAV accidents?
Is there an international regulatory body for investigating UAV accidents? Does it exist on any national level?

Welcome to aviation.SE! Are you asking if there are laws or regulations that apply to remotely piloted aircraft? It might help if you can be more specific, e.g. are you asking about one particular country or jurisdiction?

I'm not sure the concept of UAV accident currently exists. Aviation investigations are usually related to aircraft with someone on board (either a crew member, another employee, or a passenger).

Hmm... maybe that explains the guys with strange accents who showed up after I ran my Parrot into the tree branches one time too many?

The FAA does require reporting of drone accidents. I doubt they investigate them unless someone does something stupid like rams a drone into a military chopper

If the USAF loose a drone, they will often investigate it. Here's a report on a predator accident: http://www.af.mil/News/Article-Display/Article/121250/mq-1b-predator-accident-report-released/. But, the USAF is not an International Regulatory agency.

The UK's AAIB include UAV accidents as part of their reporting system. See https://www.gov.uk/government/publications/air-accident-monthly-bulletin-january-2018 for January's bulletin.

This question is rather broad, and, as worded, does not admit to a good answer beyond "no" to the first part, and "yes" to the second. That said, the rest of this answer might be useful to you.
There is no international body to investigate UAV accidents, just as there is no international body to investigate ordinary aircraft accidents. There are a great many national bodies.
In the United States, the National Transportation Safety Board is responsible for accident investigations, however, in order to get involved they would have to both know about the accident, and consider it worth investigating. The FAA requires that pilots operating under Part 107 report any accidents involving serious injury, or property damage greater than $500 (excluding the UAV) to the FAA. Presumably they would do some form of investigation to assess the remote pilot's continued suitability to hold a license. Hobbyists don't fly under part 107, however.
Other countries have their own investigation groups, such as the Air Accidents Investigation Branch in the United Kingdom. Wikipedia has a list of organizations that investigate aircraft accidents and incidents, but I have no idea how complete it is, and you would have to check each one to know what their particular policies are.


text:
Can a helicopter fly without a tail rotor?
Just wondering if a helicopter can fly without a tail rotor?

if they are built not to have it, yes; if they lose it during flight, not so much.

Research NOTAR.

look for helicopter crashes on youtube, several of them involve tail rotor loss.


text:
Sources for Aircraft Glide Ratio
I would like to gather data on the best glide ratio of different commercial aircraft. Unfortunately, it has proven non-trivial to obtain data aside from a few lucky examples.
Eurocontrol's BADA gives $c_L$ and $c_d$, which could be used to compute L/D. Unfortunately, their license explicitly prohibits comparison of different aircraft types. The open-source alternative OpenAP research project only contains data on a small number of aircraft and seems to be off in some cases (best glide ratio of a Cessna Citation II ~6).
Are L/D curves or glide polars available for commercial aircraft? Which is the best way to obtain data both for historical aircraft and current models?
I'm aware of the answers to the following questions:

"How does the Boeing 787 Dreamliner's glide ratio compare to other airliners?", gives two good examples
"Where can I find glide ratios for commercial aircraft?", gives no examples or sources
"How to calculate the Glide Ratio from Drag & Lift?", gives information on $c_{l/d}$
"How far can airplanes glide?", gives only a general overview

the table on the Wikipedia page on Gliding Flight and a few prominent forum posts:
Forum post (condorsoaring.com), no source provided

Aircraft Model
Glide Ratio

Boeing B707-320
19.4

Boeing 767-200
19.0

Douglas DC-8
17.9

Boeing 747-100
17.7

Douglas DC-10
17.7

Airbus A320
17.0

Lockeed Tristar L1011
17.0

Douglas DC-9 (1966)
16.5

Boeing B727-200
16.4

Douglas DC-3
14.7

Forum post (pprune.org), estimates etc.

Aircraft Model
Glide Ratio

B767-200
17.9

B727
~17

B757-200W
~19.5

B737-800W
~19.5

B777-200
~19

B787-8
21-22

Your table looks at least partially wrong. A Boeing 707-320 never achieved an L/D of 19.4.
If you have more reliable figures for fuel consumption, engine efficiency and range, you can use the Breguet Range Equation to determine L/D. See this answer for an application.


text:
Can a DPE do a checkride in any plane of the same class?
Do DPEs have to be certified in a specific aircraft type, or can they do a checkride in any airplane of the same class?
For example, if I have done all my training in a Cirrus SR22 and want to do my IFR in the same Cirrus SR22 that I own, can I use any DPE who can do IFR for ASEL?